In the early days of the church, when spreading the gospel, the apostles tried to convince the folks that Jesus was the promised Christ mentioned in the Scriptures. At that time the New Testament was not written yet, thus the “Scriptures” in the verses below refers to what we call the Old Testament today.
Below are some verses from the New Testament of the Bible on what the apostles said about the Old Testament and how Jesus was already foretold in the Old Testament. Please note that these verses are by no means exhaustive.
But what God foretold by the mouth of all the prophets, that his Christ would suffer, he thus fulfilled. [Acts 3:18]
Now when they had passed through Amphipolis and Apollonia, they came to Thessalonica, where there was a synagogue of the Jews. And Paul went in, as was his custom, and on three Sabbath days he reasoned with them from the Scriptures, explaining and proving that it was necessary for the Christ to suffer and to rise from the dead, and saying, “This Jesus, whom I proclaim to you, is the Christ.” [Acts 17:1-3]
For I delivered to you as of first importance what I also received: that Christ died for our sins in accordance with the Scriptures, that he was buried, that he was raised on the third day in accordance with the Scriptures [1 Corinthians 15:3-4]
For I tell you that Christ became a servant to the circumcised to show God’s truthfulness, in order to confirm the promises given to the patriarchs, and in order that the Gentiles might glorify God for his mercy. As it is written,
“Therefore I will praise you among the Gentiles,
and sing to your name.” [Romans 15:8-9]
Adapted from The Christian and the Bible Ten Basic Steps Toward Christian Maturity, Step 5 by Bright, Bill (publisher: NewLife Publications)